1
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Papi RM, Tasioulis KS, Kechagioglou PV, Papaioannou MA, Andriotis EG, Kyriakidis DA. Carbon Nanotube-Mediated Delivery of PTEN Variants: In Vitro Antitumor Activity in Breast Cancer Cells. Molecules 2024; 29:2785. [PMID: 38930850 PMCID: PMC11206347 DOI: 10.3390/molecules29122785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/27/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a crucial tumor suppressor protein with frequent mutations and alterations. Although protein therapeutics are already integral to numerous medical fields, their potential remains nascent. This study aimed to investigate the impact of stable, unphosphorylated recombinant human full-length PTEN and its truncated variants, regarding their tumor suppression activity with multiwalled-carbon nanotubes (MW-CNTs) as vehicles for their delivery in breast cancer cells (T-47D, ZR-75-1, and MCF-7). The cloning, overexpression, and purification of PTEN variants were achieved from E. coli, followed by successful binding to CNTs. Cell incubation with protein-functionalized CNTs revealed that the full-length PTEN-CNTs significantly inhibited cancer cell growth and stimulated apoptosis in ZR-75-1 and MCF-7 cells, while truncated PTEN fragments on CNTs had a lesser effect. The N-terminal fragment, despite possessing the active site, did not have the same effect as the full length PTEN, emphasizing the necessity of interaction with the C2 domain in the C-terminal tail. Our findings highlight the efficacy of full-length PTEN in inhibiting cancer growth and inducing apoptosis through the alteration of the expression levels of key apoptotic markers. In addition, the utilization of carbon nanotubes as a potent PTEN protein delivery system provides valuable insights for future applications in in vivo models and clinical studies.
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Affiliation(s)
- Rigini M. Papi
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (K.S.T.); (P.V.K.); (D.A.K.)
| | - Konstantinos S. Tasioulis
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (K.S.T.); (P.V.K.); (D.A.K.)
| | - Petros V. Kechagioglou
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (K.S.T.); (P.V.K.); (D.A.K.)
| | - Maria A. Papaioannou
- Laboratory of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | - Eleftherios G. Andriotis
- Laboratory of Organic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | - Dimitrios A. Kyriakidis
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (K.S.T.); (P.V.K.); (D.A.K.)
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2
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Yu J, Boehr DD. Regulatory mechanisms triggered by enzyme interactions with lipid membrane surfaces. Front Mol Biosci 2023; 10:1306483. [PMID: 38099197 PMCID: PMC10720463 DOI: 10.3389/fmolb.2023.1306483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/17/2023] [Indexed: 12/17/2023] Open
Abstract
Recruitment of enzymes to intracellular membranes often modulates their catalytic activity, which can be important in cell signaling and membrane trafficking. Thus, re-localization is not only important for these enzymes to gain access to their substrates, but membrane interactions often allosterically regulate enzyme function by inducing conformational changes across different time and amplitude scales. Recent structural, biophysical and computational studies have revealed how key enzymes interact with lipid membrane surfaces, and how this membrane binding regulates protein structure and function. This review summarizes the recent progress in understanding regulatory mechanisms involved in enzyme-membrane interactions.
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Affiliation(s)
| | - David D. Boehr
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
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3
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Barbernitz X, Raben DM. Phosphorylation of DGK. Adv Biol Regul 2022; 88:100941. [PMID: 36508895 DOI: 10.1016/j.jbior.2022.100941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Diacylglycerol (DAG) and phosphatidic acid (PtdOH) play important roles in a variety of signaling cascades (Carrasco and Merida, 2007; Stace and Ktistakis, 2006). Therefore, the physiological roles and regulatory mechanisms controlling the levels of these lipids are important. One class of enzymes capable of coordinating the levels of these two lipids are the diacylglycerol kinases (DGKs). DGKs catalyze the transfer of the γ-phosphate of ATP to the hydroxyl group of DAG which generates PtdOH(Merida et al., 2008; Sakane et al., 2007). As DGKs reciprocally modulate the relative levels of these two signaling lipids, it is not surprising that there is increasing interest in understanding the mechanism underlying the catalysis and regulation of these kinases. While post-translational modifications (PTMs) are often involved in enzyme regulation, there is surprisingly little information regarding the PTMs on these enzymes and their roles in modulating their activity and function. In this review, we will summarize what is known about one PTM on DGKs, phosphorylation, and the possible functions of this modification.
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Affiliation(s)
- Xin Barbernitz
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel M Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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4
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Perevalova AM, Kobelev VS, Sisakyan VG, Gulyaeva LF, Pustylnyak VO. Role of Tumor Suppressor PTEN and Its Regulation in Malignant Transformation of Endometrium. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1310-1326. [PMID: 36509719 DOI: 10.1134/s0006297922110104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Tumor-suppressive effects of PTEN are well-known, but modern evidence suggest that they are not limited to its ability to inhibit pro-oncogenic PI3K/AKT signaling pathway. Features of PTEN structure facilitate its interaction with substrates of different nature and display its activity in various ways both in the cytoplasm and in cell nuclei, which makes it possible to take a broader look at its ability to suppress tumor growth. The possible mechanisms of the loss of PTEN effects are also diverse - PTEN can be regulated at many levels, leading to change in the protein activity or its amount in the cell, while their significance for the development of malignant tumors has yet to be studied. Here we summarize the current data on the PTEN structure, its functions and changes in its regulatory mechanisms during malignant transformation of the cells, focusing on one of the most sensitive to the loss of PTEN types of malignant tumors - endometrial cancer.
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Affiliation(s)
| | - Vyacheslav S Kobelev
- Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, 630117, Russia
| | - Virab G Sisakyan
- Novosibirsk Regional Oncology Center, Novosibirsk, 630108, Russia
| | - Lyudmila F Gulyaeva
- Novosibirsk State University, Novosibirsk, 630090, Russia.,Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, 630117, Russia
| | - Vladimir O Pustylnyak
- Novosibirsk State University, Novosibirsk, 630090, Russia.,Federal Research Center of Fundamental and Translational Medicine, Novosibirsk, 630117, Russia
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5
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Kotzampasi DM, Premeti K, Papafotika A, Syropoulou V, Christoforidis S, Cournia Z, Leondaritis G. The orchestrated signaling by PI3Kα and PTEN at the membrane interface. Comput Struct Biotechnol J 2022; 20:5607-5621. [PMID: 36284707 PMCID: PMC9578963 DOI: 10.1016/j.csbj.2022.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/03/2022] [Accepted: 10/03/2022] [Indexed: 11/16/2022] Open
Abstract
The oncogene PI3Kα and the tumor suppressor PTEN represent two antagonistic enzymatic activities that regulate the interconversion of the phosphoinositide lipids PI(4,5)P2 and PI(3,4,5)P3 in membranes. As such, they are defining components of phosphoinositide-based cellular signaling and membrane trafficking pathways that regulate cell survival, growth, and proliferation, and are often deregulated in cancer. In this review, we highlight aspects of PI3Kα and PTEN interplay at the intersection of signaling and membrane trafficking. We also discuss the mechanisms of PI3Kα- and PTEN- membrane interaction and catalytic activation, which are fundamental for our understanding of the structural and allosteric implications on signaling at the membrane interface and may aid current efforts in pharmacological targeting of these proteins.
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Affiliation(s)
- Danai Maria Kotzampasi
- Biomedical Research Foundation, Academy of Athens, Athens 11527, Greece
- Department of Biology, University of Crete, Heraklion 71500, Greece
| | - Kyriaki Premeti
- Laboratory of Pharmacology, Faculty of Medicine, University of Ioannina, Ioannina 45110, Greece
| | - Alexandra Papafotika
- Laboratory of Biological Chemistry, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina 45110, Greece
- Biomedical Research Institute, Foundation for Research and Technology, Ioannina 45110, Greece
| | - Vasiliki Syropoulou
- Laboratory of Pharmacology, Faculty of Medicine, University of Ioannina, Ioannina 45110, Greece
| | - Savvas Christoforidis
- Laboratory of Biological Chemistry, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina 45110, Greece
- Biomedical Research Institute, Foundation for Research and Technology, Ioannina 45110, Greece
| | - Zoe Cournia
- Biomedical Research Foundation, Academy of Athens, Athens 11527, Greece
| | - George Leondaritis
- Laboratory of Pharmacology, Faculty of Medicine, University of Ioannina, Ioannina 45110, Greece
- Institute of Biosciences, University Research Center of Ioannina, Ioannina 45110, Greece
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6
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Smith IN, Dawson JE, Krieger J, Thacker S, Bahar I, Eng C. Structural and Dynamic Effects of PTEN C-Terminal Tail Phosphorylation. J Chem Inf Model 2022; 62:4175-4190. [PMID: 36001481 PMCID: PMC9472802 DOI: 10.1021/acs.jcim.2c00441] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Indexed: 11/28/2022]
Abstract
The phosphatase and tensin homologue deleted on chromosome 10 (PTEN) tumor suppressor gene encodes a tightly regulated dual-specificity phosphatase that serves as the master regulator of PI3K/AKT/mTOR signaling. The carboxy-terminal tail (CTT) is key to regulation and harbors multiple phosphorylation sites (Ser/Thr residues 380-385). CTT phosphorylation suppresses the phosphatase activity by inducing a stable, closed conformation. However, little is known about the mechanisms of phosphorylation-induced CTT-deactivation dynamics. Using explicit solvent microsecond molecular dynamics simulations, we show that CTT phosphorylation leads to a partially collapsed conformation, which alters the secondary structure of PTEN and induces long-range conformational rearrangements that encompass the active site. The active site rearrangements prevent localization of PTEN to the membrane, precluding lipid phosphatase activity. Notably, we have identified phosphorylation-induced allosteric coupling between the interdomain region and a hydrophobic site neighboring the active site in the phosphatase domain. Collectively, the results provide a mechanistic understanding of CTT phosphorylation dynamics and reveal potential druggable allosteric sites in a previously believed clinically undruggable protein.
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Affiliation(s)
- Iris N. Smith
- Genomic
Medicine Institute, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NE-50, Cleveland, Ohio 44195, United States
| | - Jennifer E. Dawson
- Genomic
Medicine Institute, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NE-50, Cleveland, Ohio 44195, United States
| | - James Krieger
- Department
of Computational and Systems Biology, University
of Pittsburgh, 800 Murdoch Building, 3420 Forbes Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Stetson Thacker
- Genomic
Medicine Institute, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NE-50, Cleveland, Ohio 44195, United States
- Cleveland
Clinic Lerner College of Medicine, Case
Western Reserve University, 9500 Euclid Avenue, Cleveland, Ohio 44195, United
States
| | - Ivet Bahar
- Department
of Computational and Systems Biology, University
of Pittsburgh, 800 Murdoch Building, 3420 Forbes Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Charis Eng
- Genomic
Medicine Institute, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NE-50, Cleveland, Ohio 44195, United States
- Cleveland
Clinic Lerner College of Medicine, Case
Western Reserve University, 9500 Euclid Avenue, Cleveland, Ohio 44195, United
States
- Case
Comprehensive Cancer Center, Case Western
Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
- Taussig
Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, Ohio 44195, United States
- Department
of Genetics and Genome Sciences, Case Western
Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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7
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Firnau MB, Brieger A. CK2 and the Hallmarks of Cancer. Biomedicines 2022; 10:biomedicines10081987. [PMID: 36009534 PMCID: PMC9405757 DOI: 10.3390/biomedicines10081987] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/29/2022] Open
Abstract
Cancer is a leading cause of death worldwide. Casein kinase 2 (CK2) is commonly dysregulated in cancer, impacting diverse molecular pathways. CK2 is a highly conserved serine/threonine kinase, constitutively active and ubiquitously expressed in eukaryotes. With over 500 known substrates and being estimated to be responsible for up to 10% of the human phosphoproteome, it is of significant importance. A broad spectrum of diverse types of cancer cells has been already shown to rely on disturbed CK2 levels for their survival. The hallmarks of cancer provide a rationale for understanding cancer’s common traits. They constitute the maintenance of proliferative signaling, evasion of growth suppressors, resisting cell death, enabling of replicative immortality, induction of angiogenesis, the activation of invasion and metastasis, as well as avoidance of immune destruction and dysregulation of cellular energetics. In this work, we have compiled evidence from the literature suggesting that CK2 modulates all hallmarks of cancer, thereby promoting oncogenesis and operating as a cancer driver by creating a cellular environment favorable to neoplasia.
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8
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Cui Y, Wang F, Zhang D, Huang J, Yang Y, Xu J, Gao Y, Ding H, Qu Y, Zhang W, Liu W, Pan L, Zhang L, Liu Z, Niu T, Liu T, Zheng Y. Estrogen-Responsive Gene MAST4 Regulates Myeloma Bone Disease. J Bone Miner Res 2022; 37:711-723. [PMID: 35064934 DOI: 10.1002/jbmr.4507] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 02/05/2023]
Abstract
Our previous data showed that young female multiple myeloma (MM) patients had a low frequency of osteolytic lesions. Based on this clinical observation, we found that estrogen cell signaling played a regulatory role in MM bone disease (MMBD), and the estrogen-responsive gene microtubule-associated serine/threonine kinase family member 4 (MAST4) was a critical factor. The presence of estrogen in cell cultures promoted MAST4 expression in MM cells, while knocking down estrogen receptor 1 (ESR1) inhibited MAST4 expression. Chromatin immunoprecipitation assay suggested a binding site of ESR1 on the MAST4 promoter. Bisphosphonates, such as zoledronic acid (ZOL), which was widely used in MMBD control, could stimulate MAST4 expression in MM cells by promoting ESR1 expression. MAST4 interacted with phosphatase and tensin homolog (PTEN), therefore regulating the PI3K-Akt-mTOR pathway and the expression of downstream cytokines, such as CCL2/3/4. MAST4 knockdown (MAST4-KD) or ESR1 knockdown (ESR1-KD) MM cells had repressed PTEN activity, elevated PI3K-Akt-mTOR activity, and increased CCL2/3/4 expressions. Coculture of MAST4-KD or ESR1-KD MM cells with pre-osteoclasts (pre-OCs) stimulated OC formation in vitro, whereas neutralizing antibodies of CCL2/3/4 attenuated such stimulation. In mouse models, mice inoculated with MAST4-KD or ESR1-KD MM cells had severer MMBD than control knockdown (CTR-KD). The correlations between MAST4 and ESR1 expressions in MMBD, as well as related cell signaling pathways, were confirmed in analyses using gene expression profiles (GEPs) of patients' MM cells. The negative correlation of MAST4 expression and occurrence of MMBD was further validated by patients' immunohistochemical tissue array. Overall, our data suggested that estrogen cell signaling negatively regulated MMBD through MAST4. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Yushan Cui
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Fangfang Wang
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Danfeng Zhang
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
- Department of Hematology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Jingcao Huang
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Yan Yang
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Juan Xu
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Yuhan Gao
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Hong Ding
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Ying Qu
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Wenyan Zhang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Weiping Liu
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Ling Pan
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Li Zhang
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Zhigang Liu
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Ting Niu
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Ting Liu
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
| | - Yuhuan Zheng
- Department of Hematology, West China Hospital/State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, China
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9
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Bondos SE, Dunker AK, Uversky VN. Intrinsically disordered proteins play diverse roles in cell signaling. Cell Commun Signal 2022; 20:20. [PMID: 35177069 PMCID: PMC8851865 DOI: 10.1186/s12964-022-00821-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/11/2021] [Indexed: 11/29/2022] Open
Abstract
Signaling pathways allow cells to detect and respond to a wide variety of chemical (e.g. Ca2+ or chemokine proteins) and physical stimuli (e.g., sheer stress, light). Together, these pathways form an extensive communication network that regulates basic cell activities and coordinates the function of multiple cells or tissues. The process of cell signaling imposes many demands on the proteins that comprise these pathways, including the abilities to form active and inactive states, and to engage in multiple protein interactions. Furthermore, successful signaling often requires amplifying the signal, regulating or tuning the response to the signal, combining information sourced from multiple pathways, all while ensuring fidelity of the process. This sensitivity, adaptability, and tunability are possible, in part, due to the inclusion of intrinsically disordered regions in many proteins involved in cell signaling. The goal of this collection is to highlight the many roles of intrinsic disorder in cell signaling. Following an overview of resources that can be used to study intrinsically disordered proteins, this review highlights the critical role of intrinsically disordered proteins for signaling in widely diverse organisms (animals, plants, bacteria, fungi), in every category of cell signaling pathway (autocrine, juxtacrine, intracrine, paracrine, and endocrine) and at each stage (ligand, receptor, transducer, effector, terminator) in the cell signaling process. Thus, a cell signaling pathway cannot be fully described without understanding how intrinsically disordered protein regions contribute to its function. The ubiquitous presence of intrinsic disorder in different stages of diverse cell signaling pathways suggest that more mechanisms by which disorder modulates intra- and inter-cell signals remain to be discovered.
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Affiliation(s)
- Sarah E. Bondos
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843 USA
| | - A. Keith Dunker
- Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612 USA
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Pushchino, Moscow Region, Russia 142290
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10
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The structural basis of PTEN regulation by multi-site phosphorylation. Nat Struct Mol Biol 2021; 28:858-868. [PMID: 34625746 PMCID: PMC8549118 DOI: 10.1038/s41594-021-00668-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 08/26/2021] [Indexed: 12/12/2022]
Abstract
Phosphatase and tensin homolog (PTEN) is a phosphatidylinositol-3,4,5-triphosphate (PIP3) phospholipid phosphatase that is commonly mutated or silenced in cancer. PTEN's catalytic activity, cellular membrane localization and stability are orchestrated by a cluster of C-terminal phosphorylation (phospho-C-tail) events on Ser380, Thr382, Thr383 and Ser385, but the molecular details of this multi-faceted regulation have remained uncertain. Here we use a combination of protein semisynthesis, biochemical analysis, NMR, X-ray crystallography and computational simulations on human PTEN and its sea squirt homolog, VSP, to obtain a detailed picture of how the phospho-C-tail forms a belt around the C2 and phosphatase domains of PTEN. We also visualize a previously proposed dynamic N-terminal α-helix and show that it is key for PTEN catalysis but disordered upon phospho-C-tail interaction. This structural model provides a comprehensive framework for how C-tail phosphorylation can impact PTEN's cellular functions.
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11
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D'Andrea L, Lucato CM, Marquez EA, Chang YG, Civciristov S, Mastos C, Lupton CJ, Huang C, Elmlund H, Schittenhelm RB, Mitchell CA, Whisstock JC, Halls ML, Ellisdon AM. Structural analysis of the PTEN:P-Rex2 signaling complex reveals how cancer-associated mutations coordinate to hyperactivate Rac1. Sci Signal 2021; 14:14/681/eabc4078. [PMID: 33947796 DOI: 10.1126/scisignal.abc4078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The dual-specificity phosphatase PTEN functions as a tumor suppressor by hydrolyzing PI(3,4,5)P3 to PI(4,5)P2 to inhibit PI3K-AKT signaling and cellular proliferation. P-Rex2 is a guanine nucleotide exchange factor for Rho GTPases and can be activated by Gβγ subunits downstream of G protein-coupled receptor signaling and by PI(3,4,5)P3 downstream of receptor tyrosine kinases. The PTEN:P-Rex2 complex is a commonly mutated signaling node in metastatic cancer. Assembly of the PTEN:P-Rex2 complex inhibits the activity of both proteins, and its dysregulation can drive PI3K-AKT signaling and cellular proliferation. Here, using cross-linking mass spectrometry and functional studies, we gained mechanistic insights into PTEN:P-Rex2 complex assembly and coinhibition. We found that PTEN was anchored to P-Rex2 by interactions between the PDZ-interacting motif in the PTEN C-terminal tail and the second PDZ domain of P-Rex2. This interaction bridged PTEN across the P-Rex2 surface, preventing PI(3,4,5)P3 hydrolysis. Conversely, PTEN both allosterically promoted an autoinhibited conformation of P-Rex2 and blocked its binding to Gβγ. In addition, we observed that the PTEN-deactivating mutations and P-Rex2 truncations combined to drive Rac1 activation to a greater extent than did either single variant alone. These insights enabled us to propose a class of gain-of-function, cancer-associated mutations within the PTEN:P-Rex2 interface that uncouple PTEN from the inhibition of Rac1 signaling.
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Affiliation(s)
- Laura D'Andrea
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Christina M Lucato
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Elsa A Marquez
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Yong-Gang Chang
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Srgjan Civciristov
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 Victoria, Australia
| | - Chantel Mastos
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 Victoria, Australia
| | - Christopher J Lupton
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Cheng Huang
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia.,Monash Proteomics & Metabolomics Facility, Monash University, Clayton, 3800 Victoria, Australia
| | - Hans Elmlund
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Ralf B Schittenhelm
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia.,Monash Proteomics & Metabolomics Facility, Monash University, Clayton, 3800 Victoria, Australia
| | - Christina A Mitchell
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - James C Whisstock
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia.,ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, 3800 Victoria, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052 Victoria, Australia.
| | - Andrew M Ellisdon
- Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia.
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12
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Jang H, Smith IN, Eng C, Nussinov R. The mechanism of full activation of tumor suppressor PTEN at the phosphoinositide-enriched membrane. iScience 2021; 24:102438. [PMID: 34113810 PMCID: PMC8169795 DOI: 10.1016/j.isci.2021.102438] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/15/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
Tumor suppressor PTEN, the second most highly mutated protein in cancer, dephosphorylates signaling lipid PIP3 produced by PI3Ks. Excess PIP3 promotes cell proliferation. The mechanism at the membrane of this pivotal phosphatase is unknown hindering drug discovery. Exploiting explicit solvent simulations, we tracked full-length PTEN trafficking from the cytosol to the membrane. We observed its interaction with membranes composed of zwitterionic phosphatidylcholine, anionic phosphatidylserine, and phosphoinositides, including signaling lipids PIP2 and PIP3. We tracked its moving away from the zwitterionic and getting absorbed onto anionic membrane that harbors PIP3. We followed it localizing on microdomains enriched in signaling lipids, as PI3K does, and observed PIP3 allosterically unfolding the N-terminal PIP2 binding domain, positioning it favorably for the polybasic motif interaction with PIP2. Finally, we determined PTEN catalytic action at the membrane, all in line with experimental observations, deciphering the mechanisms of how PTEN anchors to the membrane and restrains cancer. PTEN localizes on membrane microdomains enriched in phosphoinositides, as PI3K does Full PTEN activation requires both signaling lipids, PIP2 and PIP3 Strong salt bridge interactions sustain stable PTEN membrane localization Substrate-induced P loop conformational change implicates PTEN catalytic activity
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Affiliation(s)
- Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA
| | - Iris Nira Smith
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Charis Eng
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA.,Center for Personalized Genetic Healthcare, Cleveland Clinic Community Care and Population Health, Cleveland, OH 44195, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.,Germline High Risk Cancer Focus Group, Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Laboratory of Cancer Immunometabolism, National Cancer Institute, Frederick, MD 21702, USA.,Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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13
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Comprehensive in silico mutational-sensitivity analysis of PTEN establishes signature regions implicated in pathogenesis of Autism Spectrum Disorders. Genomics 2020; 113:999-1017. [PMID: 33152507 DOI: 10.1016/j.ygeno.2020.10.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/22/2020] [Accepted: 10/30/2020] [Indexed: 01/18/2023]
Abstract
An extensively studied cancer and Autism Spectrum Disorders (ASD) gene like PTEN provided an exclusive opportunity to map its mutational-landscape, compare and establish plausible genotypic predictors of ASD-associated phenotypic outcomes. Our exhaustive in silico analysis on 4252 SNPs using >30 tools identified increased mutational-density in exon7. Phosphatase domain, although evolutionarily conserved, had the most nsSNPs localised within signature regions. The evolutionarily variable C-terminal side contained the highest truncating-SNPs outside signature regions of C2 domain and most PTMs within C-tail site which displayed maximum intolerance to polymorphisms, and permitted benign but destabilising nsSNPs that enhanced its intrinsically-disordered nature. ASD-associated SNPs localised within ATP-binding motifs and Nuclear-Localising-Sequences were the most potent triggers of ASD manifestation. These, along with variations within P, WPD and TI loops, M1 within phosphatase domain, M2 and MoRFs of C2 domain, caused severe long-range conformational fluctuations altering PTEN's dynamic stability- not observed in variations outside signature regions. 3'UTR-SNPs affected 44 strong miRNA brain-specific targets; several 5' UTR-SNPs targeted transcription-factor POLR2A and 10 pathogenic Splice-Affecting-Variants were identified.
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14
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Strunk BS, Steinfeld N, Lee S, Jin N, Muñoz-Rivera C, Meeks G, Thomas A, Akemann C, Mapp AK, MacGurn JA, Weisman LS. Roles for a lipid phosphatase in the activation of its opposing lipid kinase. Mol Biol Cell 2020; 31:1835-1845. [PMID: 32583743 PMCID: PMC7525815 DOI: 10.1091/mbc.e18-09-0556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Fig4 is a phosphoinositide phosphatase that converts PI3,5P2 to PI3P. Paradoxically, mutation of Fig4 results in lower PI3,5P2, indicating that Fig4 is also required for PI3,5P2 production. Fig4 promotes elevation of PI3,5P2, in part, through stabilization of a protein complex that includes its opposing lipid kinase, Fab1, and the scaffold protein Vac14. Here we show that multiple regions of Fig4 contribute to its roles in the elevation of PI3,5P2: its catalytic site, an N-terminal disease-related surface, and a C-terminal region. We show that mutation of the Fig4 catalytic site enhances the formation of the Fab1-Vac14-Fig4 complex, and reduces the ability to elevate PI3,5P2. This suggests that independent of its lipid phosphatase function, the active site plays a role in the Fab1-Vac14-Fig4 complex. We also show that the N-terminal disease-related surface contributes to the elevation of PI3,5P2 and promotes Fig4 association with Vac14 in a manner that requires the Fig4 C-terminus. We find that the Fig4 C-terminus alone interacts with Vac14 in vivo and retains some functions of full-length Fig4. Thus, a subset of Fig4 functions are independent of its phosphatase domain and at least three regions of Fig4 play roles in the function of the Fab1-Vac14-Fig4 complex.
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Affiliation(s)
- Bethany S Strunk
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
- Department of Biology, Trinity University, San Antonio, TX 78212
| | - Noah Steinfeld
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109
| | - Sora Lee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232
| | - Natsuko Jin
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | | | - Garrison Meeks
- Department of Biology, Trinity University, San Antonio, TX 78212
| | - Asha Thomas
- Department of Biology, Trinity University, San Antonio, TX 78212
| | - Camille Akemann
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Anna K Mapp
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Jason A MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232
| | - Lois S Weisman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109
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15
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Posttranslational Regulation and Conformational Plasticity of PTEN. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a036095. [PMID: 31932468 DOI: 10.1101/cshperspect.a036095] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor that is frequently down-modulated in human cancer. PTEN inhibits the phosphatidylinositol 3-phosphate kinase (PI3K)/AKT pathway through its lipid phosphatase activity. Multiple PI3K/AKT-independent actions of PTEN, protein-phosphatase activities and functions within the nucleus have also been described. PTEN, therefore, regulates many cellular processes including cell proliferation, survival, genomic integrity, polarity, migration, and invasion. Even a modest decrease in the functional dose of PTEN may promote cancer development. Understanding the molecular and cellular mechanisms that regulate PTEN protein levels and function, and how these may go awry in cancer contexts, is, therefore, key to fully understanding the role of PTEN in tumorigenesis. Here, we discuss current knowledge on posttranslational control and conformational plasticity of PTEN, as well as therapeutic possibilities toward reestablishment of PTEN tumor-suppressor activity in cancer.
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16
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Ghalali A, Ye ZW, Högberg J, Stenius U. PTEN and PHLPP crosstalk in cancer cells and in TGFβ-activated stem cells. Biomed Pharmacother 2020; 127:110112. [PMID: 32294598 DOI: 10.1016/j.biopha.2020.110112] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022] Open
Abstract
Akt kinase regulates several cellular processes, among them growth, proliferation and survival, and has been correlated to neoplastic disease. We report here crosstalk between several Akt regulatory phosphatases that controls the level of the activated form (phosphorylated) of Akt and affects tumor cell aggressiveness. In prostate cancer cell lines, we observed that transient transfection of PTEN decreased the endogenous level of PHLPPs and in contrast, the transient transfection of PHLPPs decreased the endogenous level of PTEN. Furthermore, silencing of PTEN by siRNA resulted in increased PHLPP levels. This phenomenon was not seen in non-transformed cells or in prostate stem cells. This crosstalk promoted cancer cell invasion and was controlled by epigenetically regulated processes where activation of miRs (miR-190 and miR214), the polycomb group of proteins and DNA methylation were involved. The purinergic P2X4 receptor, which has been shown to have a role in wound healing, was identified to be the mediator of this crosstalk. We also studied prostate stem cells and found this crosstalk in the TGFβ1-activated epithelial-mesenchymal transition (EMT). The crosstalk seemed to be a natural part of EMT. In summary, we identify a crosstalk between Akt phosphatases which is not present in non-transformed prostate cells but occurs in cancer cells and stem cells transformed by TGFβ-1. This crosstalk is important for cellular invasion. BACKGROUND Phosphatases regulate the Akt oncogene. RESULTS Crosstalk between Akt phosphatases in prostate cancer cells and in TGF-β1 activated stem cells but not in non-transformed cells. CONCLUSION This back-up mechanism facilitates invasive migration of prostate stem and cancer cells. SIGNIFICANCE Characterization of Akt regulation may lead to a better understanding of tumor development and to novel strategies for treatment.
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Affiliation(s)
- Aram Ghalali
- Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden.
| | - Zhi-Wei Ye
- Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden; Department of Pharmacology, Medical University of South Carolina, United States
| | - Johan Högberg
- Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Ulla Stenius
- Institute of Environmental Medicine, Karolinska Institutet, S-171 77 Stockholm, Sweden
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17
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Abstract
The tumor suppressor phosphatase and tensin homolog on chromosome 10 (PTEN) is a tightly regulated enzyme responsible for dephosphorylating the progrowth lipid messenger molecule phosphatidylinositol 3,4,5-trisphosphate (PIP3) on the plasma membrane. The carboxy-terminal tail (CTT) of PTEN is key for regulation of the enzyme. When phosphorylated, the unstructured CTT interacts with the phosphatase-C2 superdomain to inactivate the enzyme by preventing membrane association. PTEN mutations associated with cancer also inactivate the enzyme. Alternate translation-initiation sites generate extended isoforms of PTEN, such as PTEN-L that has multiple roles in cells. The extended amino-terminal region bears a signal sequence and a polyarginine sequence to facilitate exit from and entry into cells, respectively, and a membrane-binding helix that activates the enzyme. This amino-terminal region also facilitates mitochondrial and nucleolar localization. This review explores PTEN structure and its impact on localization and regulation.
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18
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Pulido R, Mingo J, Gaafar A, Nunes-Xavier CE, Luna S, Torices L, Angulo JC, López JI. Precise Immunodetection of PTEN Protein in Human Neoplasia. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a036293. [PMID: 31501265 DOI: 10.1101/cshperspect.a036293] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PTEN is a major tumor-suppressor protein whose expression and biological activity are frequently diminished in sporadic or inherited cancers. PTEN gene deletion or loss-of-function mutations favor tumor cell growth and are commonly found in clinical practice. In addition, diminished PTEN protein expression is also frequently observed in tumor samples from cancer patients in the absence of PTEN gene alterations. This makes PTEN protein levels a potential biomarker parameter in clinical oncology, which can guide therapeutic decisions. The specific detection of PTEN protein can be achieved by using highly defined anti-PTEN monoclonal antibodies (mAbs), characterized with precision in terms of sensitivity for the detection technique, specificity for PTEN binding, and constraints of epitope recognition. This is especially relevant taking into consideration that PTEN is highly targeted by mutations and posttranslational modifications, and different PTEN protein isoforms exist. The precise characterization of anti-PTEN mAb reactivity is an important step in the validation of these reagents as diagnostic and prognostic tools in clinical oncology, including their routine use in analytical immunohistochemistry (IHC). Here, we review the current status on the use of well-defined anti-PTEN mAbs for PTEN immunodetection in the clinical context and discuss their potential usefulness and limitations for a more precise cancer diagnosis and patient benefit.
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Affiliation(s)
- Rafael Pulido
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao 48011, Spain
| | - Janire Mingo
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain
| | - Ayman Gaafar
- Department of Pathology, Cruces University Hospital, Barakaldo 48903, Spain
| | - Caroline E Nunes-Xavier
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain.,Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo N-0310, Norway
| | - Sandra Luna
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain
| | - Leire Torices
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain
| | - Javier C Angulo
- Department of Urology, University Hospital of Getafe, Getafe, Madrid 28904, Spain.,Clinical Department, European University of Madrid, Laureate Universities, Madrid 28904, Spain
| | - José I López
- Biocruces Bizkaia Health Research Institute, Barakaldo 48903, Spain.,Department of Pathology, Cruces University Hospital, Barakaldo 48903, Spain.,University of the Basque Country, Leioa 48940, Spain
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19
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Hasle N, Matreyek KA, Fowler DM. The Impact of Genetic Variants on PTEN Molecular Functions and Cellular Phenotypes. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a036228. [PMID: 31451538 DOI: 10.1101/cshperspect.a036228] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Phosphatase and tensin homolog (PTEN) is a tumor suppressor that directly regulates a diverse array of cellular phenotypes, including growth, migration, morphology, and genome stability. How a single protein impacts so many important cellular processes remains a fascinating question. This question has been partially resolved by the characterization of a slew of missense variants that alter or eliminate PTEN's various molecular functions, including its enzymatic activity, subcellular localization, and posttranslational modifications. Here, we review what is known about how PTEN variants impact molecular function and, consequently, cellular phenotype. In particular, we highlight eight informative "sentinel variants" that abrogate distinct molecular functions of PTEN. We consider two published massively parallel assays of variant effect that measured the effect of thousands of PTEN variants on protein abundance and enzymatic activity. Finally, we discuss how characterization of clinically ascertained variants, establishment of clinical sequencing databases, and massively parallel assays of variant effect yield complementary datasets for dissecting PTEN's role in disease.
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Affiliation(s)
- Nicholas Hasle
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Kenneth A Matreyek
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Douglas M Fowler
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA.,Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA.,Genetic Networks Program, CIFAR, Toronto, Ontario, M5G 1M1, Canada
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20
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Multifaceted Regulation of PTEN Subcellular Distributions and Biological Functions. Cancers (Basel) 2019; 11:cancers11091247. [PMID: 31454965 PMCID: PMC6770588 DOI: 10.3390/cancers11091247] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/15/2019] [Accepted: 08/19/2019] [Indexed: 12/19/2022] Open
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene frequently found to be inactivated in over 30% of human cancers. PTEN encodes a 54-kDa lipid phosphatase that serves as a gatekeeper of the phosphoinositide 3-kinase pathway involved in the promotion of multiple pro-tumorigenic phenotypes. Although the PTEN protein plays a pivotal role in carcinogenesis, cumulative evidence has implicated it as a key signaling molecule in several other diseases as well, such as diabetes, Alzheimer's disease, and autism spectrum disorders. This finding suggests that diverse cell types, especially differentiated cells, express PTEN. At the cellular level, PTEN is widely distributed in all subcellular compartments and organelles. Surprisingly, the cytoplasmic compartment, not the plasma membrane, is the predominant subcellular location of PTEN. More recently, the finding of a secreted 'long' isoform of PTEN and the presence of PTEN in the cell nucleus further revealed unexpected biological functions of this multifaceted molecule. At the regulatory level, PTEN activity, stability, and subcellular distribution are modulated by a fascinating array of post-translational modification events, including phosphorylation, ubiquitination, and sumoylation. Dysregulation of these regulatory mechanisms has been observed in various human diseases. In this review, we provide an up-to-date overview of the knowledge gained in the last decade on how different functional domains of PTEN regulate its biological functions, with special emphasis on its subcellular distribution. This review also highlights the findings of published studies that have reported how mutational alterations in specific PTEN domains can lead to pathogenesis in humans.
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21
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Zhao C, Tao T, Yang L, Qin Q, Wang Y, Liu H, Song R, Yang X, Wang Q, Gu S, Xiong Y, Zhao D, Wang S, Feng D, Jiang WG, Zhang J, He J. Loss of PDZK1 expression activates PI3K/AKT signaling via PTEN phosphorylation in gastric cancer. Cancer Lett 2019; 453:107-121. [DOI: 10.1016/j.canlet.2019.03.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 02/07/2023]
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Downregulation of miR-144 by triptolide enhanced p85α-PTEN complex formation causing S phase arrest of human nasopharyngeal carcinoma cells. Eur J Pharmacol 2019; 855:137-148. [PMID: 31059711 DOI: 10.1016/j.ejphar.2019.04.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 12/15/2022]
Abstract
Selective pharmacologic targeting of cell cycle regulators is a potent anti-cancer therapeutic strategy. Here, we show that caspase-3-mediated p21 cleavage involves p53 independent of triptolide (TPL)-induced S phase arrest in human type 1 nasopharyngeal carcinoma (NPC) cells. Coimmunoprecipitation studies demonstrated that TPL causes S phase cell cycle arrest by suppressing the formation of cyclin A-phosphor (p)-cyclin-dependent kinas 2 (CDK2) (Thr 39) complexes. Ectopic expression of constitutively active protein kinase B1 (Akt1) blocks the induction of S phase arrest and the suppression of cyclin A expression and CDK2 Thr 39 phosphorylation by TPL. Expression of the phosphomimetic mutant CDK2 (T39E) rescues the cells from TPL-induced S phase arrest, whereas phosphorylation-deficient CDK2 (T39A) expression regulates cell growth with significant S phase arrest and enhances TPL-triggered S phase arrest. Treatment with TPL induces an increase in the formation of complexes between unphosphorylated phosphatase and tensin homolog deleted from chromosome 10 (PTEN) and p85α in the plasma membrane. Decreased microRNA (miR)-144 expression and increased PTEN expression after TPL treatment were demonstrated, and TPL-enhanced p85α-PTEN complexes and inhibitory effects on Akt (Ser 473) phosphorylation and S phase arrest were suppressed by ectopic PTEN short hairpin RNA or miR-144 expression. Knockdown of endogenous miR-144 by miR-144 Trap upregulated PTEN expression and accordingly enhanced p85α-PTEN complex formation and S phase arrest. Collectively, the effect of TPL on S phase arrest in human NPC cells is likely to enhance the p85α-PTEN interaction in the plasma membrane by suppressing miR-144 expression, resulting in the attenuation of cyclin A-p-CDK2 (Thr 39) complex formation via Akt inactivation.
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23
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Precise definition of PTEN C-terminal epitopes and its implications in clinical oncology. NPJ Precis Oncol 2019; 3:11. [PMID: 30993208 PMCID: PMC6465295 DOI: 10.1038/s41698-019-0083-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/05/2019] [Indexed: 02/07/2023] Open
Abstract
Anti-PTEN monoclonal antibodies (mAb) are arising as important tools for immunohistochemistry (IHC) and protein quantification routine analysis in clinical oncology. Although an effort has been made to document the reliability of tumor tissue section immunostaining by anti-PTEN mAb, and to standardize their IHC use in research and in the clinical practice, the precise topological and biochemical definition of the epitope recognized by each mAb has been conventionally overlooked. In this study, six commercial anti-PTEN mAb have been validated and characterized for sensitivity and specificity by IHC and FISH, using a set of prostate and urothelial bladder tumor specimens, and by immunoblot, using PTEN positive and PTEN negative human cell lines. Immunoblot precise epitope mapping, performed using recombinant PTEN variants and mutations, revealed that all mAb recognized linear epitopes of 6–11 amino acid length at the PTEN C-terminus. Tumor-associated or disease-associated mutations at the PTEN C-terminus did not affect subcellular localization or PIP3 phosphatase activity of PTEN in cells, although resulted in specific loss of reactivity for some mAb. Furthermore, specific mimicking-phosphorylation mutations at the PTEN C-terminal region also abolished binding of specific mAb. Our study adds new evidence on the relevance of a precise epitope mapping in the validation of anti-PTEN mAb for their use in the clinics. This will be substantial to provide a more accurate diagnosis in clinical oncology based on PTEN protein expression in tumors and biological fluids.
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24
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Naderali E, Khaki AA, Rad JS, Ali-Hemmati A, Rahmati M, Charoudeh HN. Regulation and modulation of PTEN activity. Mol Biol Rep 2018; 45:2869-2881. [PMID: 30145641 DOI: 10.1007/s11033-018-4321-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 08/20/2018] [Indexed: 01/04/2023]
Abstract
PTEN (Phosphatase and tensin homolog deleted on chromosome ten) is a tumor suppressor that is frequently mutated in most human cancers. PTEN is a lipid and protein phosphatase that antagonizes PI3K/AKT pathway through lipid phosphatase activity at the plasma membrane. More recent studies showed that, in addition to the putative role of PTEN as a PI(3,4,5)P3 3-phosphatase, it is a PI(3,4)P2 3-phosphatase during stimulation of class I PI3K signaling pathway by growth factor. Although PTEN tumor suppressor function via it's lipid phosphatase activity occurs primarily in the plasma membrane, it can also be found in the nucleus, in cytoplasmic organelles and extracellular space. PTEN has also shown phosphatase independent functions in the nucleus. PTEN can exit from the cell through exosomal export or secretion and has a tumor suppressor function in adjacent cells. PTEN has a critical role in growth, the cell cycle, protein synthesis, survival, DNA repair and migration. Understanding the regulation of PTEN function, activity, stability, localization and its dysregulation outcomes and also the intracellular and extracellular role of PTEN and paracrine role of PTEN-L in tumor cells as an exogenous therapeutic agent can help to improve clinical conceptualization and treatment of cancer.
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Affiliation(s)
- Elahe Naderali
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Afshin Khaki
- Department of Anatomical sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jafar Soleymani Rad
- Department of Anatomical sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alireza Ali-Hemmati
- Department of Anatomical sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Rahmati
- Department of Clinical Biochemistry Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hojjatollah Nozad Charoudeh
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. .,Cell Therapy Research Laboratory, Drug Applied Research Center, Tabriz University of Medical Sciences, P.O. Box: 51656-65811, Tabriz, Iran.
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25
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Fricano-Kugler CJ, Getz SA, Williams MR, Zurawel AA, DeSpenza T, Frazel PW, Li M, O’Malley AJ, Moen EL, Luikart BW. Nuclear Excluded Autism-Associated Phosphatase and Tensin Homolog Mutations Dysregulate Neuronal Growth. Biol Psychiatry 2018; 84:265-277. [PMID: 29373119 PMCID: PMC5984669 DOI: 10.1016/j.biopsych.2017.11.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/01/2017] [Accepted: 11/16/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Phosphatase and tensin homolog (PTEN) negatively regulates downstream protein kinase B signaling, resulting in decreased cellular growth and proliferation. PTEN is mutated in a subset of children with autism spectrum disorder (ASD); however, the mechanism by which specific point mutations alter PTEN function is largely unknown. Here, we assessed how ASD-associated single-nucleotide variations in PTEN (ASD-PTEN) affect function. METHODS We used viral-mediated molecular substitution of human PTEN into Pten knockout mouse neurons and assessed neuronal morphology to determine the functional impact of ASD-PTEN. We employed molecular cloning to examine how PTEN's stability, subcellular localization, and catalytic activity affect neuronal growth. RESULTS We identified a set of ASD-PTEN mutations displaying altered lipid phosphatase function and subcellular localization. We demonstrated that wild-type PTEN can rescue the neuronal hypertrophy, while PTEN H93R, F241S, D252G, W274L, N276S, and D326N failed to rescue this hypertrophy. A subset of these mutations lacked nuclear localization, prompting us to examine the role of nuclear PTEN in regulating neuronal growth. We found that nuclear PTEN alone is sufficient to regulate soma size. Furthermore, forced localization of the D252G and W274L mutations into the nucleus partially restores regulation of soma size. CONCLUSIONS ASD-PTEN mutations display decreased stability, catalytic activity, and/or altered subcellular localization. Mutations lacking nuclear localization uncover a novel mechanism whereby lipid phosphatase activity in the nucleus can regulate mammalian target of rapamycin signaling and neuronal growth.
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Affiliation(s)
- Catherine J. Fricano-Kugler
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Stephanie A. Getz
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Michael R. Williams
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Ashley A. Zurawel
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Tyrone DeSpenza
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Paul W. Frazel
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Meijie Li
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756
| | - Alistair J. O’Malley
- The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA,Department of Biomedical Data Science, The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Erika L. Moen
- The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
| | - Bryan W. Luikart
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire 03756,Corresponding Author-
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Pardhi TR, Patel MS, Sudarsanam V, Vasu KK. Design, synthesis, and evaluation of 4,5,6,7-tetrahydrobenzo[ d]thiazole-based novel dual kinase inhibitors of CK2 and GSK3β. MEDCHEMCOMM 2018; 9:1472-1490. [PMID: 30288222 DOI: 10.1039/c8md00321a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 07/25/2018] [Indexed: 01/07/2023]
Abstract
Casein kinase 2 (CK2) and glycogen synthase kinase-3beta (GSK3β) are responsible for the phosphorylation of a tumor suppressor protein (PTEN) in a cooperative manner which causes its deactivation. Thus, it is essential to inhibit both kinases simultaneously to prevent PTEN deactivation more efficiently. In this study, we have designed a novel lead from Hit15 which was identified in silico as a dual kinase inhibitor against CK2 and GSK3β through our previous study. The dataset of structural analogs of the lead was designed and confirmed by pharmacophore mapping and molecular docking. The screened analogs were considered further and a series of "tetrahydrobenzo[d]thiazoles" were synthesized. Compound 1g has shown highest dual kinase inhibitory activity at a concentration of 1.9 μM against CK2 and 0.67 μM against GSK3β. Our results suggest that the presence of a carboxyl group at the meta position of the phenyl ring plays a vital role in dual kinase inhibition.
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Affiliation(s)
- Triveni R Pardhi
- Department of Natural Products , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Opp. Air force station, Palaj , Gandhinagar-382355 , Gujarat , India . ; ; Tel: +917927439375
| | - Manishkumar S Patel
- Department of Biotechnology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar-382355 , Gujarat , India
| | - V Sudarsanam
- Department of Medicinal Chemistry , B. V. Patel Pharmaceutical Education & Research Development (PERD) Centre , Ahmedabad-380054 , Gujarat , India .
| | - Kamala K Vasu
- Department of Natural Products , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Opp. Air force station, Palaj , Gandhinagar-382355 , Gujarat , India . ; ; Tel: +917927439375.,Department of Medicinal Chemistry , B. V. Patel Pharmaceutical Education & Research Development (PERD) Centre , Ahmedabad-380054 , Gujarat , India .
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Dempsey DR, Cole PA. Protein Chemical Approaches to Understanding PTEN Lipid Phosphatase Regulation. Methods Enzymol 2018; 607:405-422. [PMID: 30149868 DOI: 10.1016/bs.mie.2018.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
Since the discovery of C-tail phosphorylation of PTEN almost 20 years ago, much progress has been made in understanding its regulatory influences on the cellular function of PTEN. Phosphorylation of Ser380, Thr382, Thr383, and Ser385 drives a PTEN conformational change from an open to closed state where catalytic function is impaired, plasma membrane binding is reduced, and cellular stability is enhanced. Despite these advances, a detailed structural and mechanistic model of how these phosphorylations impact PTEN function is lacking. We discuss here several recent approaches to analyzing PTEN phosphorylation and highlight several insights that have come from this work. We also discuss remaining challenges for the PTEN regulation field and potential directions for future research.
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Affiliation(s)
- Daniel R Dempsey
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Department of Medicine, Harvard Medical School, Boston, MA, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, United States
| | - Philip A Cole
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Department of Medicine, Harvard Medical School, Boston, MA, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, United States.
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Lee YR, Chen M, Pandolfi PP. The functions and regulation of the PTEN tumour suppressor: new modes and prospects. Nat Rev Mol Cell Biol 2018; 19:547-562. [DOI: 10.1038/s41580-018-0015-0] [Citation(s) in RCA: 399] [Impact Index Per Article: 66.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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29
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Malaney P, Palumbo E, Semidey-Hurtado J, Hardee J, Stanford K, Kathiriya JJ, Patel D, Tian Z, Allen-Gipson D, Davé V. PTEN Physically Interacts with and Regulates E2F1-mediated Transcription in Lung Cancer. Cell Cycle 2018; 17:947-962. [PMID: 29108454 PMCID: PMC6103743 DOI: 10.1080/15384101.2017.1388970] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 12/13/2022] Open
Abstract
PTEN phosphorylation at its C-terminal (C-tail) serine/threonine cluster negatively regulates its tumor suppressor function. However, the consequence of such inhibition and its downstream effects in driving lung cancer remain unexplored. Herein, we ascertain the molecular mechanisms by which phosphorylation compromises PTEN function, contributing to lung cancer. Replacement of the serine/threonine residues with alanine generated PTEN-4A, a phosphorylation-deficient PTEN mutant, which suppressed lung cancer cell proliferation and migration. PTEN-4A preferentially localized to the nucleus where it suppressed E2F1-mediated transcription of cell cycle genes. PTEN-4A physically interacted with the transcription factor E2F1 and associated with chromatin at gene promoters with E2F1 DNA-binding sites, a likely mechanism for its transcriptional suppression function. Deletion analysis revealed that the C2 domain of PTEN was indispensable for suppression of E2F1-mediated transcription. Further, we uncovered cancer-associated C2 domain mutant proteins that had lost their ability to suppress E2F1-mediated transcription, supporting the concept that these mutations are oncogenic in patients. Consistent with these findings, we observed increased PTEN phosphorylation and reduced nuclear PTEN levels in lung cancer patient samples establishing phosphorylation as a bona fide inactivation mechanism for PTEN in lung cancer. Thus, use of small molecule inhibitors that hinder PTEN phosphorylation is a plausible approach to activate PTEN function in the treatment of lung cancer. Abbreviations AKT V-Akt Murine Thymoma Viral Oncogene CA Cancer adjacent CDK1 Cyclin dependent kinase 1 CENPC-C Centromere Protein C ChIP Chromatin Immunoprecipitation co-IP Co-immunoprecipitation COSMIC Catalog of Somatic Mutations In Cancer CREB cAMP Responsive Element Binding Protein C-tail Carboxy terminal tail E2F1 E2F Transcription Factor 1 ECIS Electric Cell-substrate Impedance Sensing EGFR Epidermal Growth Factor Receptor GSI Gamma Secretase Inhibitor HDAC1 Histone Deacetylase 1 HP1 Heterochromatin protein 1 KAP1/TRIM28 KRAB-Associated Protein 1/Tripartite Motif Containing 28 MAF1 Repressor of RNA polymerase III transcription MAF1 homolog MCM2 Minichromosome Maintenance Complex Component 2 miRNA micro RNA MTF1 Metal-Regulatory Transcription Factor 1 PARP Poly(ADP-Ribose) Polymerase PD-1 Programmed Cell Death 1 PD-L1 Programmed Cell Death 1 Ligand 1 PI3K Phosphatidylinositol-4,5-Bisphosphate 3-Kinase PLK Polo-like Kinase pPTEN Phosphorylated PTEN PTEN Phosphatase and Tensin Homolog deleted on chromosome ten PTM Post Translational Modification Rad51 RAD51 Recombinase Rad52 RAD52 Recombinase RPA1 Replication protein A SILAC Stable Isotope Labeling with Amino Acids in Cell Culture SRF Serum Response Factor TKI Tyrosine Kinase inhbitors TMA Tissue Microarray TOP2A DNA Topoisomerase 2A.
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Affiliation(s)
- Prerna Malaney
- Department of Pathology and Cell Biology, Morsani College of Medicine
| | - Emily Palumbo
- Department of Pathology and Cell Biology, Morsani College of Medicine
| | | | - Jamaal Hardee
- Department of Pathology and Cell Biology, Morsani College of Medicine
| | | | | | - Deepal Patel
- Department of Pathology and Cell Biology, Morsani College of Medicine
| | - Zhi Tian
- College of Pharmacy, University of South Florida, Tampa, FL 33612, United States
| | - Diane Allen-Gipson
- College of Pharmacy, University of South Florida, Tampa, FL 33612, United States
| | - Vrushank Davé
- Department of Pathology and Cell Biology, Morsani College of Medicine
- Lung Cancer Center of Excellence, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, United States
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30
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A pathogenic role for germline PTEN variants which accumulate into the nucleus. Eur J Hum Genet 2018; 26:1180-1187. [PMID: 29706633 DOI: 10.1038/s41431-018-0155-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/27/2018] [Accepted: 03/30/2018] [Indexed: 11/08/2022] Open
Abstract
The PTEN gene encodes a master regulator protein that exerts essential functions both in the cytoplasm and in the nucleus. PTEN is mutated in the germline of both patients with heterogeneous tumor syndromic diseases, categorized as PTEN hamartoma tumor syndrome (PHTS), and a group affected with autism spectrum disorders (ASD). Previous studies have unveiled the functional heterogeneity of PTEN variants found in both patient cohorts, making functional studies necessary to provide mechanistic insights related to their pathogenicity. Here, we have functionally characterized a PTEN missense variant [c.49C>G; p.(Gln17Glu); Q17E] associated to both PHTS and ASD patients. The PTEN Q17E variant displayed partially reduced PIP3-catalytic activity and normal stability in cells, as shown using S. cerevisiae and mammalian cell experimental models. Remarkably, PTEN Q17E accumulated in the nucleus, in a process involving the PTEN N-terminal nuclear localization sequence. The analysis of additional germline-associated PTEN N-terminal variants illustrated the existence of a PTEN N-terminal region whose targeting in disease causes PTEN nuclear accumulation, in parallel with defects in PIP3-catalytic activity in cells. Our findings highlight the frequent occurrence of PTEN gene mutations targeting PTEN N-terminus whose pathogenicity may be related, at least in part, with the retention of PTEN in the nucleus. This could be important for the implementation of precision therapies for patients with alterations in the PTEN pathway.
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31
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Wong CW, Or PMY, Wang Y, Li L, Li J, Yan M, Cao Y, Luk HM, Tong TMF, Leslie NR, Lo IFM, Choy KW, Chan AML. Identification of a PTEN mutation with reduced protein stability, phosphatase activity, and nuclear localization in Hong Kong patients with autistic features, neurodevelopmental delays, and macrocephaly. Autism Res 2018; 11:1098-1109. [PMID: 29608813 PMCID: PMC6220804 DOI: 10.1002/aur.1950] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 01/28/2018] [Accepted: 03/09/2018] [Indexed: 01/04/2023]
Abstract
PTEN is a tumor suppressor gene inactivated in over 30% of human cancers. It encodes a lipid phosphatase that serves as a gatekeeper of the phosphoinositide 3-kinase signaling pathway. Germline mutation frequently occurs in this gene in patients diagnosed with PTEN Hamartoma Tumor Syndrome (PHTS). PHTS individuals are characterized by macrocephaly, benign growth of multiple tissues and increased tumor risk. In addition, autistic phenotypes are found in 10-20% of individuals carrying the germline PTEN mutation with macrocephaly. In this report, 13 suspected PHTS patients were screened for mutation in the PTEN gene. A missense variant (c. 302T > C) substituting the isoleucine at codon 101 to a threonine, a single nucleotide insertion (c. 327-328insC) causing a frame shift mutation and termination at codon 109, and a nonsense variant (c. 1003C > T) truncated the protein at codon 335 were identified. The I101T mutation significantly reduced PTEN protein expression levels by 2.5- to 4.0-fold. Mechanistically, I101T reduced the protein half-life of PTEN possibly due to enhanced polyubiquitination at Lysine 13. However, the I101T mutant retained almost 30% of the lipid phosphatase activity of the wild-type protein. Finally, the I101T mutant has reduced phosphorylation at a PTEN auto-dephosphorylation site at Threonine 366 and a lowered ratio of nuclear to cytosolic protein level. These partial losses of multiple PTEN biochemical functions may contribute to the tissue overgrowth and autistic features of this PHTS patient. Autism Res 2018, 11: 1098-1109. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc. LAY SUMMARY: The genetics of autism spectrum disorders is highly complex with individual risk influenced by both genetic and environmental factors. Mutation in the human PTEN gene confers a high risk of developing autistic behavior. This report revealed that PTEN mutations occurred in 23% of a selected group of Hong Kong patients harboring autistic features with gross overgrowth symptoms. Detailed characterization of a PTEN mutation revealed reduced protein stability as one of the underlying mechanisms responsible for reduced PTEN activity.
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Affiliation(s)
- Chi Wai Wong
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Penelope Mei Yu Or
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Yubing Wang
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Lisha Li
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Jing Li
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Mingfei Yan
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ye Cao
- Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ho Ming Luk
- Clinical Genetic Service, Department of Health, Cheung Sha Wan Jockey Club Clinic, Hong Kong, SAR, China
| | - Tony Ming For Tong
- Clinical Genetic Service, Department of Health, Cheung Sha Wan Jockey Club Clinic, Hong Kong, SAR, China
| | - Nick R Leslie
- Institute of Biological Chemistry, Biophysics and Bio-engineering, Heriot Watt University, Edinburgh, Scotland, UK
| | - Ivan Fai-Man Lo
- Clinical Genetic Service, Department of Health, Cheung Sha Wan Jockey Club Clinic, Hong Kong, SAR, China
| | - Kwong Wai Choy
- Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, China.,The Chinese University of Hong Kong-Baylor College of Medicine Joint Centre For Medical Genetics, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Andrew Man Lok Chan
- School of Biomedical Sciences, Lo Kwee-Seong Integrated Biomedical Sciences Building, The Chinese University of Hong Kong, Hong Kong, SAR, China.,Brain and Mind Institute, The Chinese University of Hong Kong, Hong Kong, SAR, China
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32
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Cai J, Li R, Xu X, Zhang L, Lian R, Fang L, Huang Y, Feng X, Liu X, Li X, Zhu X, Zhang H, Wu J, Zeng M, Song E, He Y, Yin Y, Li J, Li M. CK1α suppresses lung tumour growth by stabilizing PTEN and inducing autophagy. Nat Cell Biol 2018; 20:465-478. [PMID: 29593330 DOI: 10.1038/s41556-018-0065-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/14/2018] [Indexed: 12/19/2022]
Abstract
The contribution of autophagy to cancer development remains controversial, largely owing to the fact that autophagy can be tumour suppressive or oncogenic in different biological contexts. Here, we show that in non-small-cell lung cancer (NSCLC), casein kinase 1 alpha 1 (CK1α) suppresses tumour growth by functioning as an autophagy inducer to activate an autophagy-regulating, tumour-suppressive PTEN/AKT/FOXO3a/Atg7 axis. Specifically, CK1α bound the C-terminal tail of PTEN and enhanced both PTEN stability and activity by competitively antagonizing NEDD4-1-induced PTEN polyubiquitination and abrogating PTEN phosphorylation, thereby inhibiting AKT activity and activating FOXO3a-induced transcription of Atg7. Notably, blocking CK1α-induced Atg7-dependent autophagy cooperates with oncogenic HRasV12 to initiate tumorigenesis of lung epithelial cells. An association of a CK1α-modulated autophagic program with the anti-neoplastic activities of the CK1α/PTEN/FOXO3a/Atg7 axis was demonstrated in xenografted tumour models and human NSCLC specimens. This provides insights into the biological and potentially clinical significance of autophagy in NSCLC.
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MESH Headings
- A549 Cells
- Animals
- Autophagy
- Autophagy-Related Protein 7/genetics
- Autophagy-Related Protein 7/metabolism
- Carcinoma, Non-Small-Cell Lung/enzymology
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/pathology
- Casein Kinase Ialpha/genetics
- Casein Kinase Ialpha/metabolism
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Enzyme Stability
- Female
- Forkhead Box Protein O3/genetics
- Forkhead Box Protein O3/metabolism
- Gene Expression Regulation, Neoplastic
- Genes, ras
- HCT116 Cells
- HEK293 Cells
- Humans
- Lung Neoplasms/enzymology
- Lung Neoplasms/genetics
- Lung Neoplasms/pathology
- Mice, Inbred BALB C
- Mice, Nude
- Nedd4 Ubiquitin Protein Ligases/metabolism
- PTEN Phosphohydrolase/genetics
- PTEN Phosphohydrolase/metabolism
- Phosphorylation
- Protein Binding
- Protein Interaction Domains and Motifs
- Proto-Oncogene Proteins c-akt/metabolism
- Signal Transduction
- Time Factors
- Tumor Burden
- Ubiquitination
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Affiliation(s)
- Junchao Cai
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
| | - Rong Li
- Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaonan Xu
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
- Guangdong Engineering & Technology Research Center for Disease-Model Animals, Sun Yat-sen University, Guangzhou, China
| | - Le Zhang
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Rong Lian
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Lishan Fang
- The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Yongbo Huang
- State Key Laboratory of Respiratory Diseases and Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xianming Feng
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Ximeng Liu
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Xu Li
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Xun Zhu
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Heng Zhang
- Neurosurgery Intensive Care Unit, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jueheng Wu
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Musheng Zeng
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Erwei Song
- Department of Breast Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yukai He
- Department of Medicine and Department of Biochemistry and Molecular Biology, Georgia Cancer Center, Augusta University, Augusta, GA, USA
| | - Yuxin Yin
- Department of Pathology, Institute of Systems Biomedicine, School of Basic Medicine, Peking University Health Science Center, Beijing, China
| | - Jun Li
- Department of Biochemistry, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China
| | - Mengfeng Li
- Department of Microbiology, Sun Yat-sen University Zhongshan School of Medicine, Guangzhou, China.
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China.
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Potential role of the N-MYC downstream-regulated gene family in reprogramming cancer metabolism under hypoxia. Oncotarget 2018; 7:57442-57451. [PMID: 27447861 PMCID: PMC5303000 DOI: 10.18632/oncotarget.10684] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 06/13/2016] [Indexed: 12/19/2022] Open
Abstract
Metabolic reprogramming toward aerobic glycolysis and lactate fermentation supplies cancer cells with intermediate metabolites, which are used as macromolecule precursors. The oncogene MYC contributes to such aerobic metabolism by activating the expression of numerous genes essential for glycolysis and mitochondrial biogenesis. However, to survive and evolve in a hypoxic tumor milieu, cancer cells must revise MYC-driven metabolism because the mitochondrial respiratory chain provides free electrons to generate oxygen free radicals with inefficient production of ATP due to oxygen depletion. Instead, hypoxia-inducible transcription factor hypoxia-inducible factor 1 (HIF-1) takes over the role of MYC in glycolysis, but suppresses mitochondrial biogenesis and activity to protect cells from such threats. Recently, the N-MYC downstream-regulated gene (NDRG) family has received attention as potential biomarkers of cancer prognosis. NDRGs are repressed MYC-dependently in various cancers, but induced under hypoxia because HIF-1 directly activates their promoters and indirectly de-represses them by antagonizing MYC. In this review, we summarize the current understanding of the reprogramming of cancer metabolism via the counterbalance between MYC and HIF-1, and discuss the proven and putative roles of the NDRG family in adjusting cancer metabolism according to the ambient oxygen level.
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Targeting PTEN in Colorectal Cancers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1110:55-73. [DOI: 10.1007/978-3-030-02771-1_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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35
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Abstract
The cellular hypoxic response contributes to cell transformation and tumor progression. Hypoxia-inducible factor 1 (HIF-1) is a key transcription factor that mediates transcription of genes whose products are essential for cellular adaptation to hypoxia. The activity of HIF-1 is largely regulated by the abundance of its alpha subunit (HIF-1α), which is primarily regulated by an oxygen-dependent and ubiquitin/proteasome-mediated degradation process. The HIF-1α protein level is also regulated by protein kinases through phosphorylation. Polo-like kinase 3 (Plk3) is a serine/threonine protein kinase with a tumor suppressive function. Plk3 phosphorylates and destabilizes HIF-1α. Plk3 also phosphorylates and stabilizes PTEN, a known regulator of HIF-1α stability via the PI3K pathway. Our latest study showed that the Plk3 protein is suppressed by hypoxia or nickel treatment via the ubiquitin/proteasome system. We discovered that Seven in Absentia Homologue 2 (SIAH2) is the E3 ubiquitin ligase of Plk3 and that Plk3 in turn destabilizes SIAH2. Given the role of SIAH2 in promoting stability of HIF-1α, our work reveals a novel mutual regulatory mechanism between Plk3 and SIAH2, which may function to fine-tune the cellular hypoxic response. Here we discuss the role of Plk3 in the hypoxic response and tumorigenesis in light of these latest findings.
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Affiliation(s)
- Dazhong Xu
- a Department of Pathology , New York Medical College School of Medicine , Valhalla , NY , USA
| | - Wei Dai
- b Department of Environmental Medicine , New York University Langone Medical Center , Tuxedo , NY , USA
| | - Cen Li
- a Department of Pathology , New York Medical College School of Medicine , Valhalla , NY , USA
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36
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Higgins DF, Ewart LM, Masterson E, Tennant S, Grebnev G, Prunotto M, Pomposiello S, Conde-Knape K, Martin FM, Godson C. BMP7-induced-Pten inhibits Akt and prevents renal fibrosis. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3095-3104. [PMID: 28923783 DOI: 10.1016/j.bbadis.2017.09.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 12/18/2022]
Abstract
Bone morphogenetic protein-7 (BMP-7) counteracts pro-fibrotic effects of TGFβ1 in cultured renal cells and protects from fibrosis in acute and chronic renal injury models. Using the unilateral ureteral obstruction (UUO) model of chronic renal fibrosis, we investigated the effect of exogenous-rhBMP-7 on pro-fibrotic signaling pathways mediated by TGFβ1 and hypoxia. Mice undergoing UUO were treated with vehicle or rhBMP-7 (300μg/kg i.p.) every other day for eight days and kidneys analysed for markers of fibrosis and SMAD, MAPK, and PI3K signaling. In the kidney, collecting duct and tubular epithelial cells respond to BMP-7 via activation of SMAD1/5/8. Phosphorylation of SMAD1/5/8 was reduced in UUO kidneys from vehicle-treated animals yet maintained in UUO kidneys from BMP-7-treated animals, confirming renal bioactivity of exogenous rhBMP-7. BMP-7 inhibited Collagen Iα1 and Collagen IIIα1 gene expression and Collagen I protein accumulation, while increasing expression of Collagen IVα1 in UUO kidneys. Activation of SMAD2, SMAD3, ERK, p38 and PI3K/Akt signaling occurred during fibrogenesis and BMP-7 significantly attenuated SMAD3 and Akt signaling in vivo. Analysis of renal collecting duct (mIMCD) and tubular epithelial (HK-2) cells stimulated with TGFβ1 or hypoxia (1% oxygen) to activate Akt provided further evidence that BMP-7 specifically inhibited PI3K/Akt signaling. PTEN is a negative regulator of PI3K and BMP-7 increased PTEN expression in vivo and in vitro. These data demonstrate an important mechanism by which BMP-7 orchestrates renal protection through Akt inhibition and highlights Akt inhibitors as anti-fibrotic therapeutics.
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Affiliation(s)
- Debra F Higgins
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Leah M Ewart
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Enda Masterson
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Sadhbh Tennant
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gleb Grebnev
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Marco Prunotto
- F. Hoffmann-La Roche, Dept of Metabolic and Vascular Disease, CH4070 Basel, Switzerland
| | - Sylvia Pomposiello
- F. Hoffmann-La Roche, Dept of Metabolic and Vascular Disease, CH4070 Basel, Switzerland
| | - Karin Conde-Knape
- F. Hoffmann-La Roche, Dept of Metabolic and Vascular Disease, CH4070 Basel, Switzerland
| | - Finian M Martin
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Catherine Godson
- UCD Diabetes Complications Research Centre, School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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37
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Zhang F, Wang Y, Sun P, Wang ZQ, Wang DS, Zhang DS, Wang FH, Fu JH, Xu RH, Li YH. Fibrinogen promotes malignant biological tumor behavior involving epithelial-mesenchymal transition via the p-AKT/p-mTOR pathway in esophageal squamous cell carcinoma. J Cancer Res Clin Oncol 2017; 143:2413-2424. [PMID: 28801734 DOI: 10.1007/s00432-017-2493-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/04/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE Hyperfibrinogenemia is associated with unfavorable prognosis and advanced tumor behavior in various malignancies, including esophageal squamous cell carcinoma (ESCC). However, its biological function in ESCC is unknown. The present study was designed to further validate the prognostic value of preoperative plasma hyperfibrinogenemia and evaluate the biological role of fibrinogen, as well as the underlying mechanism in ESCC. METHODS Data from 452 cases with newly diagnosed ESCC followed by curative surgery between 2006 and 2010 were retrospectively evaluated. The Clauss method was utilized to measure the preoperative plasma fibrinogen level. Correlations between the fibrinogen level and clinicopathologic characteristics and survival analysis were performed. The effects of fibrinogen on malignant behaviors, including tumor cell viability, colony formation, migration, and invasion, were also investigated. RESULTS The optimal cut-off value for plasma fibrinogen level was defined as 4.0 g/L according to recommendations. Thus, the proportion of hyperfibrinogenemia was 24.8% (112/452). Preoperative plasma hyperfibrinogenemia was significantly associated with advanced tumor length, deep tumor invasion, advanced tumor-node-metastasis stage, alcohol consumption, a higher white blood cell count, a higher platelet count, and high globulin levels. Univariate survival analysis revealed that compared to those with normal plasma fibrinogen levels, patients with hyperfibrinogenemia tended to have poorer disease-free survival (DFS) [hazard ratio (HR), 1.692; 95% confidence interval (CI), 1.304-2.196; P < 0.001] and overall survival (OS) (HR 1.864; 95% CI 1.424-2.440; P < 0.001). In the multivariate Cox regression models, these factors remained independent predictors for impaired DFS (HR 1.491; 95% CI 1.138-1.955; P = 0.004) and OS (HR 1.648; 95% CI 1.246-2.180; P < 0.001) after adjusting for other confounding variables. In addition, fibrinogen could significantly promote cell migration and invasion but not proliferation. Moreover, it could also induce epithelial-mesenchymal transition (EMT) and increase the levels of p-PTEN, p-AKT, and p-mTOR in ESCC cell lines. CONCLUSIONS Preoperative plasma hyperfibrinogenemia might serve as an independent predictor of unfavorable survival in ESCC. Furthermore, fibrinogen may promote cell motility by inducing EMT via the p-AKT/p-mTOR pathway.
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Affiliation(s)
- Fei Zhang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Yun Wang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Peng Sun
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Zhi-Qiang Wang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - De-Shen Wang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Dong-Sheng Zhang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Feng-Hua Wang
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Jian-Hua Fu
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Guangdong Esophageal Cancer Institute, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Rui-Hua Xu
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Yu-Hong Li
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, Guangdong, People's Republic of China.
- State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China.
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou, 510060, Guangdong, People's Republic of China.
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Malaney P, Uversky VN, Davé V. PTEN proteoforms in biology and disease. Cell Mol Life Sci 2017; 74:2783-2794. [PMID: 28289760 PMCID: PMC11107534 DOI: 10.1007/s00018-017-2500-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/23/2017] [Accepted: 03/02/2017] [Indexed: 01/30/2023]
Abstract
Proteoforms are specific molecular forms of protein products arising from a single gene that possess different structures and different functions. Therefore, a single gene can produce a large repertoire of proteoforms by means of allelic variations (mutations, indels, SNPs), alternative splicing and other pre-translational mechanisms, post-translational modifications (PTMs), conformational dynamics, and functioning. Resulting proteoforms that have different sizes, alternative splicing patterns, sets of post-translational modifications, protein-protein interactions, and protein-ligand interactions, might dramatically increase the functionality of the encoded protein. Herein, we have interrogated the tumor suppressor PTEN for its proteoforms and find that this protein exists in multiple forms with distinct functions and sub-cellular localizations. Furthermore, the levels of each PTEN proteoform in a given cell may affect its biological function. Indeed, the paradigm of the continuum model of tumor suppression by PTEN can be better explained by the presence of a continuum of PTEN proteoforms, diversity, and levels of which are associated with pathological outcomes than simply by the different roles of mutations in the PTEN gene. Consequently, understanding the mechanisms underlying the dysregulation of PTEN proteoforms by several genomic and non-genomic mechanisms in cancer and other diseases is imperative. We have identified different PTEN proteoforms, which control various aspects of cellular function and grouped them into three categories of intrinsic, function-induced, and inducible proteoforms. A special emphasis is given to the inducible PTEN proteoforms that are produced due to alternative translational initiation. The novel finding that PTEN forms dimers with biological implications supports the notion that PTEN proteoform-proteoform interactions may play hitherto unknown roles in cellular homeostasis and in pathogenic settings, including cancer. These PTEN proteoforms with unique properties and functionalities offer potential novel therapeutic opportunities in the treatment of various cancers and other diseases.
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Affiliation(s)
- Prerna Malaney
- Department of Pathology and Cell Biology, Morsani College of Medicine, MDC 64, University of South Florida, 12901 Bruce B Downs Blvd, Tampa, FL, 33612, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, Tampa, FL, 33612, USA
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave., Saint Petersburg, Russia, 194064
| | - Vrushank Davé
- Department of Pathology and Cell Biology, Morsani College of Medicine, MDC 64, University of South Florida, 12901 Bruce B Downs Blvd, Tampa, FL, 33612, USA.
- Department of Oncological Sciences, Morsani College of Medicine, University of South Florida, Bruce B. Downs Blvd, Tampa, FL, 33612, USA.
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Zhang XS, Hu YH, Gao HY, Lan XW, Xue YW. Downregulation of Notch1 inhibits the invasion and metastasis of human gastric cancer cells SGC7901 and MKN74 in vitro through PTEN activation and dephosphorylation of Akt and FAK. Mol Med Rep 2017. [DOI: 10.3892/mmr.2017.6791] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Sakata S, Matsuda M, Kawanabe A, Okamura Y. Domain-to-domain coupling in voltage-sensing phosphatase. Biophys Physicobiol 2017; 14:85-97. [PMID: 28744425 PMCID: PMC5515349 DOI: 10.2142/biophysico.14.0_85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/10/2017] [Indexed: 01/12/2023] Open
Abstract
Voltage-sensing phosphatase (VSP) consists of a transmembrane voltage sensor and a cytoplasmic enzyme region. The enzyme region contains the phosphatase and C2 domains, is structurally similar to the tumor suppressor phosphatase PTEN, and catalyzes the dephosphorylation of phosphoinositides. The transmembrane voltage sensor is connected to the phosphatase through a short linker region, and phosphatase activity is induced upon membrane depolarization. Although the detailed molecular characteristics of the voltage sensor domain and the enzyme region have been revealed, little is known how these two regions are coupled. In addition, it is important to know whether mechanism for coupling between the voltage sensor domain and downstream effector function is shared among other voltage sensor domain-containing proteins. Recent studies in which specific amino acid sites were genetically labeled using a fluorescent unnatural amino acid have enabled detection of the local structural changes in the cytoplasmic region of Ciona intestinalis VSP that occur with a change in membrane potential. The results of those studies provide novel insight into how the enzyme activity of the cytoplasmic region of VSP is regulated by the voltage sensor domain.
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Affiliation(s)
- Souhei Sakata
- Department of Physiology, Division of Life Sciences, Faculty of Medicine, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
| | - Makoto Matsuda
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Akira Kawanabe
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yasushi Okamura
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.,Graduate School of Frontier Bioscience, Osaka University
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TGF-β induces phosphorylation of phosphatase and tensin homolog: implications for fibrosis of the trabecular meshwork tissue in glaucoma. Sci Rep 2017; 7:812. [PMID: 28400560 PMCID: PMC5429747 DOI: 10.1038/s41598-017-00845-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/16/2017] [Indexed: 01/06/2023] Open
Abstract
Fundamental cell signaling mechanisms that regulate dynamic remodeling of the extracellular matrix (ECM) in mechanically loaded tissues are not yet clearly understood. Trabecular meshwork (TM) tissue in the eye is under constant mechanical stress and continuous remodeling of ECM is crucial to maintain normal aqueous humor drainage and intraocular pressure (IOP). However, excessive ECM remodeling can cause fibrosis of the TM as in primary open-angle glaucoma (POAG) patients, and is characterized by increased resistance to aqueous humor drainage, elevated IOP, optic nerve degeneration and blindness. Increased levels of active transforming growth factor-β2 (TGF-β2) in the aqueous humor is the main cause of fibrosis of TM in POAG patients. Herein, we report a novel finding that, in TM cells, TGF-β-induced increase in collagen expression is associated with phosphorylation of phosphatase and tensin homolog (PTEN) at residues Ser380/Thr382/383. Exogenous overexpression of a mutated form of PTEN with enhanced phosphatase activity prevented the TGF-β-induced collagen expression by TM cells. We propose that rapid alteration of PTEN activity through changes in its phosphorylation status could uniquely regulate the continuous remodeling of ECM in the normal TM. Modulating PTEN activity may have high therapeutic potential to alleviating the fibrosis of TM in POAG patients.
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Kimura M, Hashimoto N, Kusunose M, Aoyama D, Sakamoto K, Miyazaki S, Ando A, Omote N, Imaizumi K, Kawabe T, Hasegawa Y. Exogenous induction of unphosphorylated PTEN reduces TGFβ-induced extracellular matrix expressions in lung fibroblasts. Wound Repair Regen 2017; 25:86-97. [PMID: 28019709 DOI: 10.1111/wrr.12506] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 12/20/2016] [Indexed: 01/15/2023]
Abstract
Transforming growth factor β (TGFβ) plays an important role in regulating aberrant extracellular matrix (ECM) production from alveolar/epithelial cells (AECs) and fibroblasts in pulmonary fibrosis. Although the tumor suppressor gene phosphatase and tensin homologue deleted from chromosome 10 (PTEN) can negatively control many TGFβ-activated signaling pathways via the phosphatase activity, hyperactivation of the TGFβ-related signaling pathways is often observed in fibrosis. Loss of PTEN expression might cause TGFβ-induced ECM production. In addition, TGFβ was recently shown to induce loss of PTEN enzymatic activity by phosphorylating the PTEN C-terminus. Therefore, we hypothesized that exogenous transfer of unphosphorylated PTEN (PTEN4A) might lead to reduce TGFβ-induced ECM expression in not only epithelial cells but also fibroblasts. Adenovirus-based exogenous PTEN4A induction successfully reduced TGFβ-induced fibronectin expression and retained β-catenin at the cell membrane in human epithelial cells. Exogenous unphosphorylated PTEN also attenuated TGFβ-induced ECM production and inhibited TGFβ-induced β-catenin translocation in a human fibroblast cell line and in mouse primary isolated lung fibroblasts. Conversely, TGFβ-induced α-smooth muscle actin expression did not seem to be inhibited in these fibroblasts. Our data suggest that exogenous administration of unphosphorylated PTEN might be a promising strategy to restore TGFβ-induced loss of PTEN activity and reduce aberrant TGFβ-induced ECM production from epithelial cells and fibroblasts in lung fibrosis as compared with wild-type PTEN induction.
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Affiliation(s)
- Motohiro Kimura
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Naozumi Hashimoto
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masaaki Kusunose
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Aoyama
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji Sakamoto
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinichi Miyazaki
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akira Ando
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Norihiro Omote
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kazuyoshi Imaizumi
- Department of Respiratory Medicine and allergy, Fujita Health University, Toyoake, Japan
| | - Tsutomu Kawabe
- Department of Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshinori Hasegawa
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Chen Z, Thomas SN, Bolduc DM, Jiang X, Zhang X, Wolberger C, Cole PA. Enzymatic Analysis of PTEN Ubiquitylation by WWP2 and NEDD4-1 E3 Ligases. Biochemistry 2016; 55:3658-66. [PMID: 27295432 DOI: 10.1021/acs.biochem.6b00448] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PTEN is a lipid phosphatase that converts phosphatidylinositol 3,4,5-phosphate (PIP3) to phosphatidylinositol 4,5-phosphate (PIP2) and plays a critical role in the regulation of tumor growth. PTEN is subject to regulation by a variety of post-translational modifications, including phosphorylation on a C-terminal cluster of four Ser/Thr residues (380, 382, 383, and 385) and ubiquitylation by various E3 ligases, including NEDD4-1 and WWP2. It has previously been shown that C-terminal phosphorylation of PTEN can increase its cellular half-life. Using in vitro ubiquitin transfer assays, we show that WWP2 is more active than NEDD4-1 in ubiquitylating unphosphorylated PTEN. The mapping of ubiquitylation sites in PTEN by mass spectrometry showed that both NEDD4-1 and WWP2 can target a broad range of Lys residues in PTEN, although NEDD4-1 versus WWP2 showed a stronger preference for ubiquitylating PTEN's C2 domain. Whereas tetraphosphorylation of PTEN did not significantly affect its ubiquitylation by NEDD4-1, it inhibited PTEN ubiquitylation by WWP2. Single-turnover and pull-down experiments suggested that tetraphosphorylation of PTEN appears to weaken its interaction with WWP2. These studies reveal how the PTEN E3 ligases WWP2 and NEDD4-1 exhibit distinctive properties in Lys selectivity and sensitivity to PTEN phosphorylation. Our findings also provide a molecular mechanism for the connection between PTEN Ser/Thr phosphorylation and PTEN's cellular stability.
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Affiliation(s)
- Zan Chen
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
| | - Stefani N Thomas
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
| | - David M Bolduc
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
| | - Xuejun Jiang
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center , New York, New York 10065, United States
| | - Xiangbin Zhang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
| | - Cynthia Wolberger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
| | - Philip A Cole
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine , Baltimore, Maryland 21205, United States
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Li Y, Dickman M. Processing of AtBAG6 triggers autophagy and fungal resistance. PLANT SIGNALING & BEHAVIOR 2016; 11:e1175699. [PMID: 27128431 PMCID: PMC4973798 DOI: 10.1080/15592324.2016.1175699] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 03/28/2016] [Accepted: 03/29/2016] [Indexed: 05/18/2023]
Abstract
The Bcl-2-associated athanogene (BAG) family is an evolutionarily conserved, multifunctional group of cytoprotective co-chaperones. Using structural bioinformatic approaches we identified 7 homologs of the Arabidopsis BAG family. Evaluating knockouts in Arabidopsis of individual BAG family members, we noted that Arabidopsis BAG6 (AtBAG6) knockout lines exhibited a pronounced enhancement of susceptibility to the necrotrophic fungal pathogen Botrytis cinerea. Moreover, we identified a single predicted caspase-1 site that was cleaved by an aspartyl protease (AtAPCB1). Finally, we showed AtBAG6 forms a complex with AtAPCB1 via coupling to a C2 GRAM domain protein (AtBAGP1). This complex and its activation is necessary for triggering pathogen mediated autophagic cell death and host resistance.
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Affiliation(s)
- Yurong Li
- Institute for Plant Genomics and Biotechnology, Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
| | - Marty Dickman
- Institute for Plant Genomics and Biotechnology, Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
- CONTACT Marty Dickman
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Chen Z, Dempsey DR, Thomas SN, Hayward D, Bolduc DM, Cole PA. Molecular Features of Phosphatase and Tensin Homolog (PTEN) Regulation by C-terminal Phosphorylation. J Biol Chem 2016; 291:14160-14169. [PMID: 27226612 DOI: 10.1074/jbc.m116.728980] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Indexed: 12/27/2022] Open
Abstract
PTEN is a tumor suppressor that functions to negatively regulate the PI3K/AKT pathway as the lipid phosphatase for phosphatidylinositol 3,4,5-triphosphate. Phosphorylation of a cluster of Ser/Thr residues (amino acids 380-385) on the C-terminal tail serves to alter the conformational state of PTEN from an open active state to a closed inhibited state, resulting in a reduction of plasma membrane localization and inhibition of enzyme activity. The relative contribution of each phosphorylation site to PTEN autoinhibition and the structural basis for the conformational closure is still unclear. To further the structural understanding of PTEN regulation by C-terminal tail phosphorylation, we used protein semisynthesis to insert stoichiometric and site-specific phospho-Ser/Thr(s) in the C-terminal tail of PTEN. Additionally, we employed photo-cross-linking to map the intramolecular PTEN interactions of the phospho-tail. Systematic evaluation of the PTEN C-tail phospho-cluster showed autoinhibition, and conformational closure was influenced by the aggregate effect of multiple phospho-sites rather than dominated by a single phosphorylation site. Moreover, photo-cross-linking suggested a direct interaction between the PTEN C-tail and a segment in the N-terminal region of the catalytic domain. Mutagenesis experiments provided additional insights into how the PTEN phospho-tail interacts with both the C2 and catalytic domains.
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Affiliation(s)
- Zan Chen
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - Daniel R Dempsey
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - Stefani N Thomas
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - Dawn Hayward
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - David M Bolduc
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - Philip A Cole
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205.
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Kohnoh T, Hashimoto N, Ando A, Sakamoto K, Miyazaki S, Aoyama D, Kusunose M, Kimura M, Omote N, Imaizumi K, Kawabe T, Hasegawa Y. Hypoxia-induced modulation of PTEN activity and EMT phenotypes in lung cancers. Cancer Cell Int 2016; 16:33. [PMID: 27095949 PMCID: PMC4836157 DOI: 10.1186/s12935-016-0308-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 04/11/2016] [Indexed: 01/11/2023] Open
Abstract
Background Persistent hypoxia stimulation, one of the most critical microenvironmental factors, accelerates the acquisition of epithelial–mesenchymal transition (EMT) phenotypes in lung cancer cells. Loss of phosphatase and tensin homologue deleted from chromosome 10 (PTEN) expression might accelerate the development of lung cancer in vivo. Recent studies suggest that tumor microenvironmental factors might modulate the PTEN activity though a decrease in total PTEN expression and an increase in phosphorylation of the PTEN C-terminus (p-PTEN), resulting in the acquisition of the EMT phenotypes. Nevertheless, it is not known whether persistent hypoxia can modulate PTEN phosphatase activity or whether hypoxia-induced EMT phenotypes are negatively regulated by the PTEN phosphatase activity. We aimed to investigate hypoxia-induced modulation of PTEN activity and EMT phenotypes in lung cancers. Methods Western blotting was performed in five lung cancer cell lines to evaluate total PTEN expression levels and the PTEN activation. In a xenograft model of lung cancer cells with endogenous PTEN expression, the PTEN expression was evaluated by immunohistochemistry. To examine the effect of hypoxia on phenotypic alterations in lung cancer cells in vitro, the cells were cultured under hypoxia. The effect of unphosphorylated PTEN (PTEN4A) induction on hypoxia-induced EMT phenotypes was evaluated, by using a Dox-dependent gene expression system. Results Lung cancer cells involving the EMT phenotypes showed a decrease in total PTEN expression and an increase in p-PTEN. In a xenograft model, loss of PTEN expression was observed in the tumor lesions showing tissue hypoxia. Persistent hypoxia yielded an approximately eight-fold increase in the p-PTEN/PTEN ratio in vitro. PTEN4A did not affect stabilization of hypoxia-inducible factor 1α. PTEN4A blunted hypoxia-induced EMT via inhibition of β-catenin translocation into the cytoplasm and nucleus. Conclusion Our study strengthens the therapeutic possibility that compensatory induction of unphosphorylated PTEN may inhibit the acquisition of EMT phenotypes in lung cancer cells under persistent hypoxia.
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Affiliation(s)
- Takashi Kohnoh
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Naozumi Hashimoto
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Akira Ando
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Koji Sakamoto
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Shinichi Miyazaki
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Daisuke Aoyama
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Masaaki Kusunose
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Motohiro Kimura
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Norihito Omote
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
| | - Kazuyoshi Imaizumi
- Department of Respiratory Medicine and Allergy, Fujita Health University, Toyoake, Japan
| | - Tsutomu Kawabe
- Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshinori Hasegawa
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-Ku, Nagoya 466-8550 Japan
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Abstract
PTEN subcellular localization is fundamental in the execution of the distinct PTEN biological activities, including not only its PI(3,4,5)P3 phosphatase activity when associated to membranes but also its subcellular compartment-specific interactions with regulatory and effector proteins, including those exerted in the nucleus. As a consequence, PTEN subcellular localization is tightly regulated in vivo by both intrinsic and extrinsic mechanisms. The plasma membrane/nucleus/cytoplasm partitioning of PTEN has been the focus of several studies, both from a mechanistic and from a disease-association point of view. Here, we summarize the current knowledge on PTEN plasma membrane/nucleus/cytoplasm distribution, and present subcellular fractionation, immunofluorescence, and immunohistochemical methods to study the distribution and shuttling of PTEN between these subcellular compartments.
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Affiliation(s)
- Anabel Gil
- Centro de Investigación Príncipe Felipe, Valencia, 46013, Spain
- Department of Hematology and Medical Oncology, Biomedical Research Institute INCLIVA, Valencia, 46010, Spain
| | - José I López
- Department of Pathology, Cruces University Hospital, University of the Basque Country (UPV/EHU), Barakaldo, 48903, Spain
- Biocruces Health Research Institute, Plaza de Cruces s/n, Barakaldo, Bizkaia, 48903, Spain
| | - Rafael Pulido
- Centro de Investigación Príncipe Felipe, Valencia, 46013, Spain.
- Biocruces Health Research Institute, Plaza de Cruces s/n, Barakaldo, Bizkaia, 48903, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48013, Spain.
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Protein Kinase CK2: A Targetable BCR-ABL Partner in Philadelphia Positive Leukemias. Adv Hematol 2015; 2015:612567. [PMID: 26843864 PMCID: PMC4710905 DOI: 10.1155/2015/612567] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/20/2015] [Indexed: 12/23/2022] Open
Abstract
BCR-ABL-mediated leukemias, either Chronic Myeloid Leukemia (CML) or Philadelphia positive Acute Lymphoblastic Leukemia (ALL), are the paradigm of targeted molecular therapy of cancer due to the impressive clinical responses obtained with BCR-ABL specific tyrosine kinase inhibitors (TKIs). However, BCR-ABL TKIs do not allow completely eradicating both CML and ALL. Furthermore, ALL therapy is associated with much worse responses to TKIs than those observed in CML. The identification of additional pathways that mediate BCR-ABL leukemogenesis is indeed mandatory to achieve synthetic lethality together with TKI. Here, we review the role of BCR-ABL/protein kinase CK2 interaction in BCR-ABL leukemias, with potentially relevant implications for therapy.
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Morotti A, Panuzzo C, Crivellaro S, Carrà G, Fava C, Guerrasio A, Pandolfi PP, Saglio G. BCR-ABL inactivates cytosolic PTEN through Casein Kinase II mediated tail phosphorylation. Cell Cycle 2015; 14:973-9. [PMID: 25608112 DOI: 10.1080/15384101.2015.1006970] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The tumor suppressive function of PTEN is exerted within 2 different cellular compartments. In the cytosol-membrane, it negatively regulates PI3K-AKT pathway through the de-phosphorylation of phosphatidylinositol (3,4,5)-triphosphate (PIP3), therefore blocking one of the major signaling transduction pathways in tumorigenesis. In the nucleus, PTEN controls genomic stability and cellular proliferation through phosphatase independent mechanisms. Importantly, impairments in PTEN cellular compartmentalization, changes in protein levels and post-transductional modifications affect PTEN tumor suppressive functions. Targeting mechanisms that inactivate PTEN promotes apoptosis induction of cancer cells, without affecting normal cells, with appealing therapeutic implications. Recently, we have shown that BCR-ABL promotes PTEN nuclear exclusion by favoring HAUSP mediated PTEN de-ubiquitination in Chronic Myeloid Leukemia. Here, we show that nuclear exclusion of PTEN is associated with PTEN inactivation in the cytoplasm of CML cells. In particular, BCR-ABL promotes Casein Kinase II-mediated PTEN tail phosphorylation with consequent inhibition of the phosphatase activity toward PIP3. Targeting Casein Kinase II promotes PTEN reactivation with apoptosis induction. We therefore propose a novel BCR-ABL/CKII/PTEN pathway as a potential target to achieve synthetic lethality with tyrosine kinase inhibitors.
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Affiliation(s)
- Alessandro Morotti
- a Department of Clinical and Biological Sciences; San Luigi Hospital ; Orbassano - Turin University ; Turin , Italy
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50
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Kusunose M, Hashimoto N, Kimura M, Ogata R, Aoyama D, Sakamoto K, Miyazaki S, Ando A, Omote N, Imaizumi K, Kawabe T, Hasegawa Y. Direct regulation of transforming growth factor β-induced epithelial-mesenchymal transition by the protein phosphatase activity of unphosphorylated PTEN in lung cancer cells. Cancer Sci 2015; 106:1693-704. [PMID: 26450531 PMCID: PMC4714667 DOI: 10.1111/cas.12831] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/30/2015] [Accepted: 10/04/2015] [Indexed: 12/29/2022] Open
Abstract
Transforming growth factor β (TGFβ) causes the acquisition of epithelial-mesenchymal transition (EMT). Although the tumor suppressor gene PTEN (phosphatase and tensin homologue deleted from chromosome 10) can negatively regulate many signaling pathways activated by TGFβ, hyperactivation of these signaling pathways is observed in lung cancer cells. We recently showed that PTEN might be subject to TGFβ-induced phosphorylation of its C-terminus, resulting in a loss of its enzyme activities; PTEN with an unphosphorylated C-terminus (PTEN4A), but not PTEN wild, inhibits TGFβ-induced EMT. Nevertheless, whether or not the blockade of TGFβ-induced EMT by the PTEN phosphatase activity might be attributed to the unphosphorylated PTEN C-terminus itself has not been fully determined. Furthermore, the lipid phosphatase activity of PTEN is well characterized, whereas the protein phosphatase activity has not been determined. By using lung cancer cells carrying PTEN domain deletions or point mutants, we investigated the role of PTEN protein phosphatase activities on TGFβ-induced EMT in lung cancer cells. The unphosphorylated PTEN C-terminus might not directly retain the phosphatase activities and repress TGFβ-induced EMT; the modification that keeps the PTEN C-terminus not phosphorylated might enable PTEN to retain the phosphatase activity. PTEN4A with G129E mutation, which lacks lipid phosphatase activity but retains protein phosphatase activity, repressed TGFβ-induced EMT. Furthermore, the protein phosphatase activity of PTEN4A depended on an essential association between the C2 and phosphatase domains. These data suggest that the protein phosphatase activity of PTEN with an unphosphorylated C-terminus might be a therapeutic target to negatively regulate TGFβ-induced EMT in lung cancer cells.
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Affiliation(s)
- Masaaki Kusunose
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Naozumi Hashimoto
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Motohiro Kimura
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Ryo Ogata
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Daisuke Aoyama
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Koji Sakamoto
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Shinichi Miyazaki
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Akira Ando
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Norihito Omote
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
| | - Kazuyoshi Imaizumi
- Department of Respiratory Medicine and AllergyFujita Health UniversityToyoakeJapan
| | - Tsutomu Kawabe
- Department of Pathophysiological Laboratory SciencesNagoya University Graduate School of MedicineNagoyaJapan
| | - Yoshinori Hasegawa
- Department of Respiratory MedicineNagoya University Graduate School of MedicineNagoyaJapan
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